No. 20. Kelly McGonigal wants you to make stress your friend.

When Stanford psychologist Kelly McGonigal first told her audience that a belief in the harmful effects of stress — and not stress itself — was a serious health risk, many people laughed.

But by the end of her talk, most of them were willing to accept changing their perception of stress to that of a normal physical reaction preparing your body for action. Key to this shift: a support group of loved ones.

Keith Barry is well-known in Europe for his mind-blowing stunts. Some call him a magician, others call him a brain hacker. Whatever the name, Barry entertains with "brain magic," composing routines that exploit the human mind's loopholes and bugs. The effect is a revealing look into the complex software between our ears.

No. 18. Elizabeth Gilbert says that everyone is a genius.

TED

Views: 11 million

Elizabeth Gilbert, author of "Eat, Pray, Love," discusses the impossible expectations we have for people we call geniuses. Instead of labeling a select few people as geniuses, she believes that we all have something in us that is genius. Gilbert says, "I have had work or ideas come through me from a source that I honestly cannot identify. What is that thing?"

No. 17. David Blaine explains how he held his breath underwater for 17 minutes.

TED

Views: 11 million

Magician David Blaine reveals how he hit this world record and why he chooses to put his life on the line to entertain audiences. When he decided to see how long he could hold his breath, for example, a surgeon told him that anything longer than six minutes would risk serious brain damage. "So, I took that as a challenge," Blaine says.

No. 15. Dan Gilbert reveals the science behind happiness.

TED

Views: 12 million

Harvard psychologist Dan Gilbert explains the fallacy behind the notion that to achieve happiness, people must get what they want. He uses psychology and neuroscience to explain that what we think makes us happy is, often, wrong.

As Gilbert says, "Natural happiness is what we get when we get what we wanted, and synthetic happiness is what we make when we don't get what we wanted. In our society, we have a strong belief that synthetic happiness is of an inferior kind."

No. 14. David Gallo shares the mystery behind the sea creatures of the deep.

TED

Views: 12 million

A pioneer in ocean exploration, David Gallo provides us with a look at life miles below the ocean's surface. Included in the footage of his explorations are a cuttlefish that changes colors, a camouflaged, nearly invisible octopus, and a neon fish.

"Today we've only explored about 3% of what's out there in the ocean," he tells the audience. "Already we've found the world's highest mountains, the world's deepest valleys, underwater lakes, underwater waterfalls ... There's still 97%, and either that 97% is empty or just full of surprises."

No. 13. Pamela Meyer reveals how to spot a liar.

TED

Views: 12 million

"Liespotting" author Pamela Meyer says we're facing an epidemic of dishonesty, when on any given day you may be lied to anywhere from 10 to 200 times.

You can train yourself to spot the subtle cues of deception, she says, by listening for qualifying language ("to tell you the truth ...") and watching for uncharacteristic body language, like too much eye contact or a fake smile.

No. 12. Shawn Achor shares the happy secret to better work.

TED

Views: 12 million

Being happy at work isn't just a perk, argues psychologist Shawn Achor: Happiness fuels productivity.

"If you can raise somebody's level of positivity in the present, then their brain experiences what we now call a happiness advantage, which is your brain at positive performs significantly better than it does at negative, neutral, or stressed," he says. "Your intelligence rises, your creativity rises, your energy levels rise. In fact, what we've found is that every single business outcome improves."

No. 11. Susan Cain describes the secret power of introverts.

The author of a best-selling book, "Quiet: The Power of Introverts in a World That Can't Stop Talking," argues that charismatic talkers tend to overshadow thoughtful introverts — which can be a problem, since the loudest person in the room is not always the smartest or most creative. The quieter types among us have plenty to bring to the table and can make excellent leaders, she says.

No. 10. Cameron Russell describes what it's like to be a supermodel.

TED

Views: 13 million

The Victoria's Secret model knows that she "won a genetic lottery," but she also admits that she is insecure, since she has to think about what she looks like every day.

"If you ever are wondering, 'If I have thinner thighs and shinier hair, will I be happier?' you just need to meet a group of models, because they have the thinnest thighs and the shiniest hair and the coolest clothes, and they're the most physically insecure women probably on the planet," she says.

No. 9. Pranav Mistry takes a look at the beginnings of wearable technology.

TED

Views: 14 million

Pranav Mistry's 2009 talk is an interesting look at wearable technology in its infancy.

While the video has lost its ability to awe over the years, it remains a charming peek inside Mistry's mind at this time, since he would go on to become a Samsung executive responsible for breakthroughs in smartwatches.

No. 8. Dan Pink delves into the science behind motivation.

TED

Views: 15 million

Previously a speech writer for Al Gore, Dan Pink is now a career analyst, studying the puzzle of motivation. He offers advice to managers who want to get the most out of their employees. First off, he tells them to forget the traditional forms of reward that, in the end, actually "dull thinking and block creativity."

No. 6. Mary Roach reveals some surprising science about sex.

TED

Views: 18 million

The topic isn't the only reason this talk is so popular — it's also the humor and wit of Mary Roach. She details her findings from hours of obscure research into the unknown and centuries-old topic of the orgasm. In the end, she gives viewers 10 bold and surprising claims about sexual climax. Viewer discretion is advised.

No. 5. Jill Bolte Taylor demonstrates what a stroke does to the brain.

TED

Views: 18 million

Jill Bolte Taylor, a brain scientist, learned firsthand what a stroke does to the human mind when a blood vessel in her brain burst one morning.

Witnessing her motion, speech, and self-awareness shut down one by one, Bolte spent the next eight years relearning how to think, walk, and talk. While the left side of her brain was permanently damaged, the right side experienced a windfall of creative energy. Today, she serves as a powerful voice for brain recovery.

No. 4. Brené Brown discusses the power of vulnerability, courage, authenticity, and shame.

TED

Views: 24 million

These four emotions and characteristics are things we come into contact with every day, and Brené Brown has spent the last 10 years studying them. In a speech filled with quotable material, her most poignant remark may be this: "You're imperfect, and you're wired for struggle, but you are worthy of love and belonging."

No. 2. Amy Cuddy explains how your body language shapes who you are.

Social psychologist Amy Cuddy details the scientific evidence behind power posing. Her research shows that the way you sit, stand, and hold yourself not only affects the way others perceive you, but changes your body chemistry.

She explains how assuming a high-power pose, like standing with your feet spread and planting your hands on your hips, can increase your feelings of dominance and lower your stress.

No. 1. Sir Ken Robinson says that schools are killing our creativity.

Sir Ken Robinson tops the list with his speech that calls into question our whole conception of education. As Robinson explains, we need to radically rethink our schools, encouraging and cultivating creativity and acknowledging the presence of multiple types of intelligence.

Robinson believes that we are educating people out of their creativity. "If you're not prepared to be wrong, you'll never come up with anything original," Robinson says.